| 1. |
- Andersson, Åsa, et al.
(författare)
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Pivotal Advance : HMGB1 expression in active lesions of human and experimental multiple sclerosis
- 2008
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Ingår i: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 0741-5400 .- 1938-3673. ; 84:5, s. 1248-1255
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Forskningsöversikt (refereegranskat)abstract
- Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating disease of the CNS, most frequently starting with a series of bouts, each followed by complete remission and then a secondary, progressive phase during which the neurological deficit increases steadily. The underlying molecular mechanisms responsible for disease progression are still unclear. Herein, we demonstrate that high mobility group box chromosomal protein 1 (HMGB1), a DNA-binding protein with proinflammatory properties, is evident in active lesions of MS and experimental autoimmune encephalomyelitis (EAE) and that HMGB1 levels correlate with active inflammation. Furthermore, the expression of the innate HMGB1 receptors--receptor for advanced glycation end products, TLR2, and TLR4--was also highly increased in MS and rodent EAE. Additionally, in vitro activation of rodent CNS-derived microglia and bone marrow-derived macrophages demonstrated that microglia were equally as capable as macrophages of translocating HMGB1 following LPS/IFN-gamma stimulation. Significant expression of HMGB1 and its receptors on accumulating activated macrophages and resident microglia may thus provide a positive feedback loop that amplifies the inflammatory response during MS and EAE pathogenesis.
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| 2. |
- Beecham, Ashley H, et al.
(författare)
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Analysis of immune-related loci identifies 48 new susceptibility variants for multiple sclerosis.
- 2013
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 45:11, s. 1353-60
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Tidskriftsartikel (refereegranskat)abstract
- Using the ImmunoChip custom genotyping array, we analyzed 14,498 subjects with multiple sclerosis and 24,091 healthy controls for 161,311 autosomal variants and identified 135 potentially associated regions (P < 1.0 × 10(-4)). In a replication phase, we combined these data with previous genome-wide association study (GWAS) data from an independent 14,802 subjects with multiple sclerosis and 26,703 healthy controls. In these 80,094 individuals of European ancestry, we identified 48 new susceptibility variants (P < 5.0 × 10(-8)), 3 of which we found after conditioning on previously identified variants. Thus, there are now 110 established multiple sclerosis risk variants at 103 discrete loci outside of the major histocompatibility complex. With high-resolution Bayesian fine mapping, we identified five regions where one variant accounted for more than 50% of the posterior probability of association. This study enhances the catalog of multiple sclerosis risk variants and illustrates the value of fine mapping in the resolution of GWAS signals.
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| 3. |
- Bridel, Claire, et al.
(författare)
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Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology : A Systematic Review and Meta-analysis
- 2019
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Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149 .- 2168-6157. ; 76:9, s. 1035-1048
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Forskningsöversikt (refereegranskat)abstract
- Importance Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.Objectives To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.Data Sources PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.Study Selection Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.Data Extraction and Synthesis Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.Main Outcome and Measure The cNfL levels adjusted for age and sex across diagnoses.Results Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.Conclusions and Relevance These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.
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| 4. |
- Bronge, Mattias, et al.
(författare)
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Identification of four novel T cell autoantigens and personal autoreactive profiles in multiple sclerosis
- 2022
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 8:17
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Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS), in which pathological T cells, likely autoimmune, play a key role. Despite its central importance, the autoantigen repertoire remains largely uncharacterized. Using a novel in vitro antigen delivery method combined with the Human Protein Atlas library, we screened for T cell autoreactivity against 63 CNS-expressed proteins. We identified four previously unreported autoantigens in MS: fatty acid-binding protein 7, prokineticin-2, reticulon-3, and synaptosomal-associated protein 91, which were verified to induce interferon-gamma responses in MS in two cohorts. Autoreactive profiles were heterogeneous, and reactivity to several autoantigens was MS-selective. Autoreactive T cells were predominantly CD4(+) and human leukocyte antigen-DR restricted. Mouse immunization induced antigen-specific responses and CNS leukocyte infiltration. This represents one of the largest systematic efforts to date in the search for MS autoantigens, demonstrates the heterogeneity of autoreactive profiles, and highlights promising targets for future diagnostic tools and immunomodulatory therapies in MS.
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| 5. |
- Burkill, Sarah, et al.
(författare)
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Pharmacological Treatments Preceding Diagnosis Of Progressive Multifocal Leukencephalopathy
- 2016
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Ingår i: Pharmacoepidemiology and Drug Safety. - : Wiley-Blackwell. - 1053-8569 .- 1099-1557. ; 25:Suppl. 3, s. 496-497
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Progressive multifocal leukencephalopathy (PML) is a rare, often fatal viral disease, which affects the white matter of the brain. It is caused by John Cunningham (JC) polyomavirus, which is present in most people and is usually harm-less. For immunocompromised persons, such as those who are taking immunosuppressive treatments, the risk of JC virus causing PML is increased, although still rare. As PML diagnosis is not always accurate, epidemiology of PML, including the true incidence and patient characteristics, is incompletely described.Objectives: To identify pharmacological treatments preceding diagnosis of definitive, probable and possible PML, after excluding incorrect PML diagnoses by medical record review.Methods: Patients with a PML diagnosis in Sweden between 1988 and 2013 were identified through the Patient register using ICD 9 code 046D and ICD 10code A81.2 (n = 281). Medical records were reviewed and information on clinical characteristics and pharmacological treatments were collected. Each of the diagnoses was determined as definite PML, possible PML, probable PML or non-PML based on the consensus statement for the AAN neuroinfectious disease section published in 2013. (PMCID: 3662270).Results: Medical records for 251 patients (89%) were available and examined. In total, 84 (33%) of the 251 PML diagnoses were confirmed. For those with a record of being exposed to immunosuppressant drugs, 60 (65%) of the 92 records were confirmed as being definite PML. Among 12 patients exposed to rituximab 11 (92%) had definite and 1 (8%) had probable PML. For the 9 natalizumab users, 8 (89%) had definite PML and 1 (11%) was diagnosed incorrectly.Conclusions: A substantial proportion of PML diagnoses recorded in Sweden are incorrect, however amongst those exposed to immunosuppressants such as rituximab and natalizumab the majority of diagnoses are correct. Assessing immunosuppressive drug history could be an important part of the diagnostic processes for PML.
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| 6. |
- Covacu, Ruxandra, et al.
(författare)
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Nitric oxide exposure diverts neural stem cell fate from neurogenesis towards astrogliogenesis
- 2006
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1066-5099 .- 1549-4918. ; 178, s. 268-268
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Regeneration of cells in the central nervous system is a process that might be affected during neurological disease and trauma. Because nitric oxide (NO) and its derivatives are powerful mediators in the inflammatory cascade, we have investigated the effects of pathophysiological concentrations of NO on neurogenesis, gliogenesis, and the expression of proneural genes in primary adult neural stem cell cultures. After exposure to NO, neurogenesis was downregulated, and this corresponded to decreased expression of the proneural gene neurogenin-2 and beta-III-tubulin. The decreased ability to generate neurons was also found to be transmitted to the progeny of the cells. NO exposure was instead beneficial for astroglial differentiation, which was confirmed by increased activation of the Janus tyrosine kinase/signal transducer and activator of transcription transduction pathway. Our findings reveal a new role for NO during neuroinflammatory conditions, whereby its proastroglial fate-determining effect on neural stem cells might directly influence the neuroregenerative process.
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| 7. |
- Danilov, Alexandre, et al.
(författare)
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Neurogenesis in the adult spinal cord in an experimental model of multiple sclerosis
- 2006
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Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 23:2, s. 394-400
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Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis is an inflammatory disease of the central nervous system characterized by inflammation, demyelination, axonal degeneration and accumulation of neurological disability. Previously, we demonstrated that stem cells constitute a possible endogenous source for remyelination. We now addressed the question of whether neurogenesis can occur in neuroinflammatory lesions. We demonstrated that, in experimental autoimmune encephalomyelitis, induced in rats 1,1'-dioctadecyl-6,6'-di(4sulphopentyl)-3,3,3',3'tetramethylindocarbocyani n(DiI)-labelled ependymal cells not only proliferated but descendants migrated to the area of neuroinflammation and differentiated into cells expressing the neuronal markers beta-III-tubulin and NeuN. Furthermore, these cells were immunoreactive for bromodeoxyuridine and PCNA, markers for cells undergoing cell proliferation. Using the whole-cell patch-clamp technique on freshly isolated 1, DiI-labelled cells from spinal cord lesions we demonstrated the ability of these cells to fire overshooting action potentials similar to those of immature neurones. We thus provide the first evidence for the initiation of neurogenesis in neuroinflammatory lesions in the adult spinal cord.
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| 8. |
- Dias, David O., et al.
(författare)
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Pericyte-derived fibrotic scarring is conserved across diverse central nervous system lesions
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Fibrotic scar tissue limits central nervous system regeneration in adult mammals. The extent of fibrotic tissue generation and distribution of stromal cells across different lesions in the brain and spinal cord has not been systematically investigated in mice and humans. Furthermore, it is unknown whether scar-forming stromal cells have the same origin throughout the central nervous system and in different types of lesions. In the current study, we compared fibrotic scarring in human pathological tissue and corresponding mouse models of penetrating and non-penetrating spinal cord injury, traumatic brain injury, ischemic stroke, multiple sclerosis and glioblastoma. We show that the extent and distribution of stromal cells are specific to the type of lesion and, in most cases, similar between mice and humans. Employing in vivo lineage tracing, we report that in all mouse models that develop fibrotic tissue, the primary source of scar-forming fibroblasts is a discrete subset of perivascular cells, termed type A pericytes. Perivascular cells with a type A pericyte marker profile also exist in the human brain and spinal cord. We uncover type A pericyte-derived fibrosis as a conserved mechanism that may be explored as a therapeutic target to improve recovery after central nervous system lesions.
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| 9. |
- Fagerlund, Michael, et al.
(författare)
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Proliferation, migration and differentiation of ependymal region neural progenitor cells in the brainstem after hypoglossal nerve avulsion
- 2011
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Ingår i: Restorative Neurology and Neuroscience. - 1878-3627. ; 29:1, s. 47-59
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Cells in the ependymal region in the adult central nervous system (CNS) have been found to possess neural progenitor cell (NPC) like features including capacity for generating new neurons and glia in response to injury and inflammatory disease. Whether these cells are activated after a peripheral nerve injury has not previously been extensively evaluated. Methods: We investigate the possible activation and effect of NPCs in the ependymal region in the immediate vicinity to the hypoglossal nucleus in the brainstem using two models of injuries, hypoglossal nerve transection and nerve avulsion after which the proliferation, migration and differentiation of ependymal regional NPCs were evaluated. Results: We showed that: (i) immunoreactivity for Sox2 was detected in cells in the ependymal region of the brainstem and that BrdU/Sox2-positive cells were observed after avulsion, but not after transection injury; (ii) avulsion induces re-expression of nestin in the ependymal layer as well as induced NPC migration from the ependymal layer; (iii) the chemokine SDF-1 alpha (a marker for migrating cells) was upregulated ipsilateral to the nerve injury; (iiii) the NPCs migrating differentiated only into GFAP-positive astrocytes in the hypoglossal nucleus. Conclusion: These results suggest that nerve avulsion injury induces in parallel with the retrograde "axon reaction" activation of endogenous NPCs in the ependymal region and further suggest that these cells could be involved in repair and neuroregeneration after injury within the brainstem.
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| 10. |
- Gahm, Caroline, et al.
(författare)
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Reduced neuronal injury after treatment with NG-nitro-L-arginine methyl ester (L-NAME) or 2-sulfo-phenyl-N-tert-butyl nitrone (S-PBN) following experimental brain contusion
- 2005
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Ingår i: Neurosurgery. - : Ovid Technologies (Wolters Kluwer Health). - 0148-396X .- 1524-4040. ; 57:6, s. 1272-1281
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Nitric oxide (NO) and oxygen free radicals are implicated in the pathophysiology of traumatic brain injury (TBI). Peroxynitrite formation from NO and superoxide contributes to secondary neuronal injury but the neuroprotective effects of nitric oxide synthase (NOS)-inhibitors have been contradictory. This study was undertaken to examine whether PTtic administration of the (NOS)-inhibitor N-nitro-l-arginine methyl ester (L-NAME), and a combination of L-NAME and the nitrone radical scavenger 2-sulfo-phenyl-N-tert-butyl nitrone (S-PBN) favorable affects neuronal injury in a model of TBI. METHODS: A weight-drop model of TBI was used. The animals received L-NAME, S-PBN or a combination of the drugs 15 minutes prothrombin time (PT) and sacrificed after 24 hours or six days. NOS activity was measured by the conversion of L-[U-C]arginine to L-[U-C]citrulline. Peroxynitrite formation, cellular apoptosis, neuronal degeneration and survival were assessed by nitrotyrosine-, TUNEL-, Fluoro-Jade- and NeuN-stainings. RESULTS: eNOS and nNOS activity was significantly reduced in animals that received L-NAME alone or the combination with S-PBN. iNOS activity or iNOS immunoreactivity was not affected. All treatments significantly reduced neuronal degeneration and nitrotyrosine immunoreactivity at 24 hours and increased neuronal survival at six days PT. No differences were detected between L-NAME and L-NAME + S-PBN groups. CONCLUSION: NO from NOS contributes to secondary neuronal injury in this TBI-model. PTtic treatment does not inhibit early beneficial NO-related effects. L-NAME and S-PBN limit peroxynitrite formation, promoting neuronal survival. The combination of L-NAME and S-PBN was neuroprotective; surprisingly no additive effects were found on nitrotyrosine formation, apoptosis or neuronal survival.
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